package com.moon.server.service.data;

import com.moon.server.entity.all.StaticData;
import com.moon.server.entity.data.PointEntity;
import com.moon.server.helper.FileHelper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.gdal.gdal.Dataset;
import org.gdal.gdal.gdal;
import org.gdal.ogr.Geometry;
import org.gdal.ogr.ogr;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

/**
 * 栅格分析服务
 * @author WWW
 * @date 2023-11-16
 */
@Service
public class SlopeAnalysisService {
    @Value("${sys.path.slopFile}")
    private String filePath;

    private String xlsTemplate;

    private final static Log log = LogFactory.getLog(SlopeAnalysisService.class);

    /**
     * 获取Excel模板
     */
    private String getXlsTemplate() {
        if (null == xlsTemplate) {
            xlsTemplate = FileHelper.getClassPath() + File.separator + "config" + File.separator + "slop.xlsx";
        }

        return xlsTemplate;
    }

    /**
     * 下载坡度分析Excel
     */
    public void downloadSlopXls(Geometry polygon, HttpServletResponse res) throws Exception {
        Dataset ds = null;
        try {
            ds = gdal.Open(filePath);
            if (null == ds) {
                throw new Exception("打开栅格数据失败");
            }

            List<PointEntity> list = analysisPolygon(polygon, ds);
            if (null == list || list.isEmpty()) {
                throw new Exception("分析结果为空（查询范围无效）");
            }

            //
        } finally {
            if (null != ds) {
                ds.delete();
            }
        }
    }

    /**
     * 分析多边形
     */
    public List<PointEntity> analysisPolygon(Geometry geo, Dataset ds) {
        double[] transform = ds.GetGeoTransform();
        int xSize = ds.getRasterXSize(), ySize = ds.getRasterYSize();
        double minX = transform[0], pixelWidth = transform[1], maxY = transform[3], pixelHeight = Math.abs(transform[5]);
        double[] env = new double[4];
        geo.GetEnvelope(env);

        int xMinPixel = Math.max((int) Math.floor((env[0] - minX) / pixelWidth), 1);
        int yMinPixel = Math.max((int) Math.floor((maxY - env[3]) / pixelHeight), 1);
        int xMaxPixel = Math.min((int) Math.floor((env[1] - minX) / pixelWidth), xSize);
        int yMaxPixel = Math.min((int) Math.floor((maxY - env[2]) / pixelHeight), ySize);
        if (xMaxPixel < 1 || yMaxPixel < 1 || xMaxPixel - xMinPixel < 0 || yMaxPixel - yMinPixel < 0) {
            return null;
        }

        double[] values = new double[1];
        List<PointEntity> list = new ArrayList<>();
        for (int y = yMinPixel; y <= yMaxPixel; y++) {
            for (int x = xMinPixel; x <= xMaxPixel; x++) {
                Geometry point = new Geometry(ogr.wkbPoint);
                point.AddPoint(minX + pixelWidth * x, maxY - pixelHeight * y);
                if (!geo.Intersects(point)) {
                    continue;
                }

                ds.GetRasterBand(StaticData.I1).ReadRaster(x, y, 1, 1, values);
                if (!Double.isNaN(values[0])) {
                    list.add(new PointEntity(point.GetY(), point.GetX(), values[0]));
                }
            }
        }

        return list;
    }
}